1. Field of the Invention
This invention relates to methods of detecting errors in a network environment. Specifically, this invention relates to methods of detecting faulty network interface cards within a computer system.
2. Related Art
Personal computers (PCs) have undergone evolutionary changes since the original models based on the Intel 8088 microprocessor, such as the International Business Machine Corporation (IBM) PC and other IBM-compatible machines. As the popularity of PCs have grown, so has the demand for more advanced features and increased capability, reliability and speed. Higher order microprocessors such as the Intel 20286, 30386, 40486, and more recently, the Pentium series have been developed. The speed of the fastest of these processors, the Pentium II series is 266 MHz as opposed to the 8 MHz clock speed for the 8088 microprocessor.
Faster bus architectures have been developed to support the higher processor speeds. Modem computer systems typically include one or more processors coupled through a system bus to main memory. The system bus also typically couples to a high bandwidth expansion bus, such as the Peripheral Component Interconnect (PCI) bus which operates at 33 MHz and is capable of transferring data at a rate of 133 MBps. High speed devices such as small computer systems interface (SCSI) adapters, network interface cards (NIC), video adapters, etc. can be coupled to a PCI bus. An older type low bandwidth bus such as the Industry Standard Architecture (ISA), also referred to as the AT bus, is generally coupled to the system bus as well. This bus operates at 6 MHz. To the ISA bus are attached various low speed devices such as keyboard, Basic Input/Output System (BIOS) and parallel and communications ports. These devices are known as legacy devices because they trace their lineage, their legacy, back to the initial PC architecture introduced by IBM in 1982.
With the enhanced processor and bus speeds the PC now is utilized to perform as a server, and to provide high speed data transfers between, for example, a network and a storage device. However, because modem PCs are not designed to provide very sophisticated levels of fault tolerance, systems and methods must be devised to protect users from hardware failures. This is particularly important in server computers. For example, there is currently no inexpensive and direct mechanism for allowing a PC using one or more arbitrary LAN protocols to contain several network interface cards that act in a fault tolerant manner so that if one fails, the other card automatically takes over responsibility for routing network server traffic. Thus, a need exists for a simple, inexpensive system that allows multiple network interface cards to reside within a standard personal computer and provide fault tolerant capabilities.